Prior to transporting harvested produce to market, one of the major tasks which must be performed is that of properly sorting the produce and packaging the produce for distribution. Typically, produce is sorted and packaged using a number of criteria, including size, weight, shape, color, quality, and quantity.
The presorting of produce has a number of advantages for both consumers and produce growers. For example, through presorting, poor or spoiled produce can be removed prior to packaging, thereby reducing the likelihood of spoilage of the remaining produce during subsequent transportation and storage. The presorting of produce also permits consumers to purchase produce having general characteristics which are compatible with their needs. A restaurant owner, for example, may desire consistently to purchase some types of produce so that all of the pieces of such produce are of a substantially uniform size and quality. Further, the presorting of produce facilitates packaging and storing, since the sorted produce may usually be neatly arranged on trays or in crates.
In the past, the sorting of produce has been accomplished in a number of ways. Originally, produce was sorted entirely by hand, with the sorters being given instructions and training relating to the predetermined sorting criteria. Such a sorting method is tedious and quite imperfect, giving rise to numerous errors due to both human inconsistency and to varying applications of the sorting criteria by different individuals. Accordingly, although some hand sorting is still carried out in the produce industry, most produce sorting is now done mechanically.
Now that a considerable amount of the presorting of produce is done mechanically, the sorting function is completed much faster than sorting by hand. Throughput of the produce during sorting and packaging has been dramatically improved, but there still remains problems. If the produce cannot be sorted and packaged rapidly enough, some produce rots in the fields or reaches the marketplace in less than optimum condition. In order to stretch out the harvest season, some items of produce are harvested early and not allowed to ripen in the fields, but rather ripen in transit or on a shelf at the home of the consumer. This practice does not provide consumers with the most nutritious or pleasing produce. The best produce is that which is ripened in the fields and rushed to the consumer while still in its optimum condition. Hence, there is an extreme amount of pressure to harvest the produce and rush it to the consumer as rapidly as possible.
Due to the above-mentioned pressures and drawbacks, attempts have been made to develop more efficient and reliable methods for sorting produce mechanically. One of the most promising sorting methods currently in use involves scanning the produce optically in order to ascertain its characteristics. This sorting method offers the potential for greatly increasing the speed, accuracy and reliability of sorting by size, as well as the opportunity to sort on the basis of other visual characteristics.
Although the structural requirements for a suitable optical sorting apparatus vary somewhat depending upon the type of objects to be sorted, an effective optical sorting apparatus must generally perform three separate operations. First, the objects must be singulated (i.e., the individual objects must be separated physically one from another). Secondly, each object must then be individually scanned or examined in order to ascertain its characteristics. Finally, the individual objects must be sorted mechanically based upon the information obtained during scanning. Thus, an effective sorting apparatus must make provisions for effective singulating, scanning, and mechanical sorting.
These three individual functions may be performed, either by a single machine, or by a number of separate cooperating devices. Some optical sorting systems are quite complex and process a large amount of produce in a short time.
After the produce is presorted, it must be packaged for distribution. Such packaging is accomplished using various types of receptacles such as cartons, boxes, bags, and crates. Since throughput is so critically important, the speed of the packaging process must be capable of matching or exceeding the speed of the sorting process where multiple automated sorting lines may be used to feed a single box or carton filler.
To complicate matters, governmental regulatory requirements for various types of produce may require information about the produce such as an exact count or the average weight of each article of produce within the receptacle. When such information is required, the throughput of the produce at the packaging stage can be significantly hindered. With presently known box or carton fillers, it simply takes time to count each individual article of produce as it is placed in the receptacle and/or to determine, with any degree of accuracy, the average weight of each article of produce.
In an effort to address the needs for throughput and required information about the produce, a few automated box or carton fillers have been developed. One such device relies on detecting weight and inferring the count of articles within the receptacle. First, the device rough-fills the receptacle to almost full using an electronic spring trip activated at a rough weight. Then, articles of produce are trickled in one at a time, weighing after each new addition, until the desired weight is obtained. Since the articles are presorted and a size range is known for each article, the average weight for each article can be estimated and an estimate of the total count of articles within the receptacle can be made.
Another device utilizes a slightly different approach. First, the device crude fills the receptacle to almost full using an electronic weighing mechanism. Then, by estimating the average weight of the articles, the number of articles needed to fill the receptacle to a predetermined count is calculated and added to the receptacle. The added weight is determined so that the actual average weight of the added articles is determined. That average weight is assumed to hold true for the entire contents of the receptacle. The device then accumulates the calculation over time so that a running tally of the average weight of the added articles is determined.
Both of these devices have significant deficiencies. The former device infers the count from the weight and the weight is assessed after each article is trickled in one at a time. This repeated weighing slows the packaging process. Additionally, the count and the average weight are estimated rather than precise and accurate. With the latter device, the average weight of the articles within each receptacle is inferred and the average weight of the articles added to each receptacle is calculated and averaged over time. Although this device is faster than the former device, it still infers the total count and the average weight of the articles within any given receptacle.
What is needed in the produce sorting and packaging industry is a box or carton filler that accurately counts the articles of produce, can accurately fill to a desired weight, and is capable of calculating the average weight of the articles of produce within each receptacle without sacrificing throughput.